I. Field of the Disclosure
The technology of the disclosure relates generally to distributed voltage network circuits, and specifically to measuring voltage and current within such circuits.
II. Background
Thermal emissions are a problem of increasing concern in integrated circuit (IC) design. High temperatures in an IC may cause carrier mobility degradation, which may slow down operation of the IC, increase resistivity, and/or cause circuit failures. This problem has become especially critical as voltage scaling has slowed down and the number of active components per unit area has increased. In this regard, the temperature of an IC fabricated on a semiconductor die, such as a microprocessor or cache memory, may be determined or estimated based on current measurement within the IC. As a non-limiting example, current measurement within an IC may be used to determine whether the current within the IC exceeds a defined current threshold. If the measured current within the IC exceeds the defined current threshold, a control system corresponding to the IC may be configured to perform certain functions that improve IC performance, such as preventing the IC from overheating.
Although on-die current measurement of an IC on a semiconductor die may be used to estimate temperature of the IC, accurately measuring current within the IC may be difficult. In particular, because voltage distribution, and hence current distribution, may differ across distributed circuit elements within an IC, the current profile of a particular area of an IC is not necessarily indicative of the current profile of other areas of the IC or the entire IC. For example, a first current distributed to a first area of an IC may be different from a second current distributed to a second area of the IC. Thus, measuring current in one particular area of an IC may not provide an accurate representation of overall current within the IC. Inaccurate current measurements within the IC results in inaccurate temperature estimations within the IC, which may then reduce the effectiveness of temperature-based functions configured to improve performance of an IC.
In this regard, it would be advantageous to more accurately measure on-die current in light of varying voltage and current profiles across distributed elements within an IC. In particular, providing more accurate on-die current measurements may improve results generated by functions within a corresponding control system that use the current measurement to increase system performance.